Last year's horrifying natural disaster in Japan sent shockwaves around the world in more ways than one. The meltdown at Fukushima was a stark reminder of what can happen when nuclear power gets out of our control. Some nations responded to the catastrophe by shutting down plants and announcing ambitious phase-out plans — leading some to speculate that the age of nuclear power is coming to an end. But shutting down all nuclear power plants is easier said than done.

Is the nuclear power era really over? Or does our future still involve atomic energy in some form? Let's look at the evidence.

Nuclear power is quickly losing its luster among governments and citizens around the globe. Soon after the Fukushima disaster, Germany shut down half of its plants and announced a complete phase-out plan. Switzerland did the same, proclaiming that no new plants would be built on its soil and that its five existing plants would cease operations by 2034. Even before Fukushima there were a number of countries working on nuclear phase-outs, including Austria, Sweden, and Belgium. The Italians voted overwhelmingly to stay nuclear-free, while Taiwan and Mexico are considering significant scale-backs.

And Japan, the country hardest hit by the disaster — and arguably the country most dependent on nuclear energy — shut down its last functioning power plant in early May 2012, marking the first time since 1970 that the country has gone nuclear power-free.

Accompanying many of these pronouncements were plans to develop renewable energy sources. In consideration of global warming, these countries recognize that reverting back to carbon-emitting fossil fuels is not the answer. The Fukushima disaster, it would seem, has inspired a renewed focus on the development of clean, effective, and safe energy sources for the 21st century.

Given these trends, you might think the age of nuclear power is coming to an end, a short-lived experiment that featured as many benefits as it did risks.

But given the costs, logistical demands, and environmental impacts of such a proposition, shutting down plants and going green is turning out to be a major challenge. Moreover, the jury's still not out on the perceived perils of nuclear power. Will the trend of nuclear phase-outs continue after the memory of Fukushima has faded somewhat? It's an open question.

The German experience

Outside of Japan, no other country responded to the Fukushima disaster as dramatically as Germany. Within weeks of the meltdown, Germany shut down eight of its 17 nuclear reactors and passed a law to phase out the remaining nine by 2022.

At the same time, Germany finds itself in the midst of a green revolution. Never keen on nuclear power in the first place, many Germans feel confident about abandoning the old energy strategy on account of the tremendous progress they've made in developing renewable energy. Wind, water, solar and thermal energy sources now account for nearly 20% of Germany's electricity output, a number the government estimates will double in 10 years. And according to European energy monitors, Germany produces more electricity from its renewable sources than it can use, on days when their offshore wind turbines spin at full tilt. In fact, on some days they have to shut down the turbines because they're producing more energy than the Germans can handle.

Renewable energy in Germany saves about 126 million tonnes of CO2 each year. It's also created more than 400,000 new jobs and stabilized energy prices. The country plans on being 100% renewable by 2050. And yet, the German government recently cut subsidies to renewable energy companies by 30%. The transition to green energy, it would seem, is not going as well as it first appears.

Chancellor Angela Merkel recently admitted that the country's plan to go completely renewable is running behind schedule. Moreover, she acknowledged that the costs of doing so are escalating dramatically. Producing all the required renewable power is one thing - distributing it across the entire country is quite another. They're now estimating the costs of expanding the energy grid at €20 billion, or nearly $25 billion, over the course of the next decade. They're even using the phrase "generational project" to describe the scope of their efforts.

Germany has also been pouring money into biomass plants and solar installations. Millions of panels now sit on German roofs and fields. But despite recent technological improvements, solar power is still far more expensive to generate than wind, gas or nuclear power — and output can be highly seasonal.

To make matters even more uncomfortable for Germans, electricity prices are expected to rise by €35 to €40 ($50 to $60) per household each year. Despite the fact that nuclear energy costs less than newer options, German law stipulates that renewable energy must be purchased first — even if it's more expensive.

The Hidden Costs of Nuclear Power

There are a number of reasons to be skeptical of nuclear power as a viable and ongoing power source. As disasters in Chernobyl and Fukushima have revealed, the results of a meltdown are devastating to the environment and the people around it. Radioactive contamination has a huge impact on all facets of life and renders large swaths of land completely unlivable for decades, if not centuries. The inherent risks, some people believe, are simply not worth it. Besides natural disasters like Fukushima, there's always the possibility of human error, or even "perfect storms" of accidents, unintended consequences, and faulty designs.

There's also the issue of security. Nuclear reactors become prime targets during military conflicts and have been repeatedly attacked during military air strikes, occupations, invasions and campaigns — the most notable incidents occurring in Iraq, Israel, and Syria. Americans in particular don't need to be reminded of this threat; the 9/11 terror attacks were a grim reminder of this possibility. In fact, back in 1972 three hijackers took control of a domestic passenger flight along the east coast of the U.S. and threatened to crash the plane into a U.S. nuclear weapons plant in Oak Ridge, Tennessee. The plane got as close as 8,000 feet above the site before the hijackers' demands were met.

And even for those plants that don't experience problems, there is still the issue of waste management; the long-term radioactive waste storage problems of nuclear power have yet to be fully solved.

And lastly, there's the ongoing threat of nuclear proliferation. Nuclear critics contend that it's not possible to discriminate between civil and military usage, and that nuclear power contributes to the proliferation of nuclear weapons.

Not dead yet

Despite these concerns, a lot can still be said on behalf of nuclear power. Perhaps the most potent argument in its favor is our ongoing climate crisis. Apart from the huge waste management issue, nuclear reactors are clean. They don't spew carbon into the atmosphere — and given the amount of energy they produce, this is no small thing. As it stands, oil reserves are dwindling while electricity demand keeps rising. Given the global warming crisis, some see the suggestion of reverting back to fossil fuels as complete folly.

Nuclear energy also offers energy independence. In some countries there may be no viable alternative. As the French are prone to say, "We have no coal, we have no oil, we have no gas, we have no choice."

And looking at the bigger picture, some would argue that there have only been five major incidents involving a nuclear power plant: namely Kyshtym, Windscale, Three Mile Island, Chernobyl, and Fukushima. By most standards, these are extremely rare occurrences. Yet others would say that these are five incidents too many.

Learn to love it...for now

There's also the challenge of moving away from nuclear. It currently provides about 6% of the world's electricity, with the U.S., France, and Japan together accounting for about half of nuclear-generated electricity in the world. According to the IAEA, as of 2007 there were over 439 nuclear power reactors in operation around the globe. Transitioning away from all this power will take time, money, and lots of resolve. It will also require more viable alternatives.

In Germany, electricity producers are having to scramble to ensure an adequate supply, as the distribution infrastructure is proving inadequate. Citizens and companies are getting increasingly nervous about whether their lights and assembly lines will stay up and running. And as Joachim Knebel of the Karlsruhe Institute of Technology has pointed out, Germany has survived this experiment only by importing electricity from neighboring France and the Czech Republic, which generate much of their power with nuclear reactors.

The situation in Japan is worse. Now that the country has shut down its last power plant, the Japanese are preparing for a summer of blackouts. Prior to this past May, Japan relied on 50 reactors for its electricity, providing almost 30% of the country's total need. To deal with the power crisis, factories are operating at night and during weekends to avoid putting too much stress on the country's power grids. Many firms are planning on implementing similar measures, while others are considering plans to generate their own power.

And like Germany, they are doing their best to promote the use of renewable energy. A new law has taken effect requiring power companies to purchase renewable energy at a fixed price for a fixed length of time. The feed-in tariff law includes energy from solar, wind, geothermal, minihydro, and biomass. The tariffs required of energy companies to pay by the law are among the highest in the world.

Japan is clearly going through a transition, and the country may come out of it stronger, cleaner, and more sustainable than before. In the meantime, however, the Japanese are having to rely on carbon emitting coal and the acquisition of electricity from neighboring countries.

At the same time, not everyone is thinking of decommissioning nuclear power plants. Countries like France and the United States have very little incentive to phase out nuclear power. Some countries are even looking to expand. Finland was the first western European nation to build more nuclear energy plants after the Chernobyl accident, and it has not been deterred after Fukushima — Finland is going ahead with its fifth nuclear reactor, and has plans to build two more. The same can be said for China, which has 25 plants currently under construction, with plans to build many more. India is also going full steam ahead with its plans, despite a growing anti-nuke sentiment.

It's clear that the writing is not yet on the wall for nuclear power — but that doesn't mean it's here to stay. Assuming that countries like Japan and Germany can undergo successful phase-outs and introduce viable renewable energy alternatives, other countries may gain inspiration and model similar plans of their own. There may also be a black swan development in energy, with the introduction of something new (like fission) or something completely unpredictable. But this is not likely to happen for many decades, even under the most optimistic of estimates.

Unless, of course, another nuclear disaster shocks the world into action.